Maybe I just thought that maybe americans are civilized enough not to hang people for being gay or rape women for being lesbians?
Well, again you're making an assertion that nobody is trying to contradict. Nobody's saying Ron Paul is going to hang the gays.
But his record contains anti-gay bills that he sponsored, and e.g. his ending of SCOTUS from being able to hear cases on the Establishment Clause could permit some very nasty things (such as sodomy laws) to return. One brief look at what the individual states have been up to this year should be enough to make one shudder at the thought of them being given that opportunity. Not to mention that he would effectively ban abortion in half the country by making Roe v. Wade null and void. (Probably
more than half the country after a short while when you look at how pervasive the attack on abortion rights has been this year. They would waste no time in slamming various anti-choice legislations through in the states that have a fully GOP-controlled house and a Republican governor.)
Then there's the deeply racist and homophobic comments he made in his newsletters which span over several decades, which he initially defended, later tried to roll back as having been ghostwritten and published without his consent, and then later denied to have any knowledge of. You know. In case anyone forgot that.